高层建筑电梯活塞效应及烟气控制分析

在电梯运行活塞效应及其对火灾烟气影响理论分析基础上,分析电梯井和前室加压及压力波动情况;结合高层建筑烟控系统的原理,通过合理的压差设计,可保证电梯系统在最大容许压差和最小容许压差之间正常工作。通过对活塞效应及其对电梯与建筑空间之间压差影响的分析发现,极限状态下烟气可能卷入电梯井和前室,对人员的疏散造成威胁,提出了控制活塞效应影响的上限临界压差。研究表明,合理的排气泄压系统、气压式挡烟系统、可变送风系统及火灾层带通风排烟设施的系统等均能对火灾烟气进行有效控制,提高电梯疏散的安全性。研究所得的结论为火灾中利用电梯进行疏散提供了理论指导及一种烟气控制的方法。

Piston Effect of Elevators in High-rise Building and Analysis of Smoke Control

Based on the theoretical analysis of piston effect,hoistway pressurization,lobby pressurization and pressure fluctuations are analyzed.Pressure difference should be designed according to the rules of smoke control systems in high-rise buildings so that elevator systems can operate normally between the maximum and minimum allowable pressure differences.According to the theoretical analysis of piston effect and its influence on the pressure difference from the elevator lobby to the rest of the building,it could result in smoke infiltration into the elevator lobby and threaten the fire evacuation in extreme cases.Furthermore,the upper limit of pressure difference is proposed to control the influence of piston effect.It shows that smoke can be kept under effective control with reasonable pressure relief vent system,barometric damper system,variable-supply air system,and system with fire floor venting or exhaust to improve the safety of evacuation by elevators.The result provides theoretical direction for evacuation by elevators.